Authentication device, frame display method, and authentication program

Abstract

To provide an authentication device that allows an object person to be photographed to smoothly perform personal authentication, regardless of height of the object person to be photographed.SOLUTION: In an authentication device 10, a camera 11 photographs an image including a face image that is an image of a face of an object person to be photographed; a touch screen 12 displays the face image; a display control unit 18 displays, on the touch screen 12, a guide frame for guiding the object person to be photographed to a photographing position of a face of the object person to be photographed, on the basis of a display position of the face image on the touch screen 12; and a personal authentication unit 17 performs, when the face image fits in the guide frame, personal authentication using the face image.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to an authentication device, a frame display method, and an authentication program.

Background Art

[0002] An authentication device that performs authentication using an image of an individual's face (hereinafter sometimes referred to as a "face image") is known. For example, the authentication device performs authentication by comparing a face image registered in an IC card with a face image captured by a camera included in the authentication device. Since an unspecified number of individuals with various heights can be authentication targets in the authentication device, a camera having a wide-angle lens (hereinafter sometimes referred to as a "wide-angle camera") is attached to the authentication device.

[0003] In a wide-angle camera, distortion in the peripheral region of the visual field increases. Therefore, there is an authentication device that displays, on a display unit included in the authentication device, a guide frame (hereinafter sometimes referred to as a "face guide frame") for guiding the face photographing position to the person being photographed, together with the face image captured by the wide-angle camera. By adjusting the position of the face so that the face image fits within the face guide frame, it is possible to prevent a decrease in the authentication rate of the authentication of the person.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] As described above, since authentication devices can authenticate a large number of individuals of varying heights, it is inconvenient if the display position of the face guide frame on the display unit is fixed. In particular, it is difficult for shorter individuals to adjust their height by stretching to fit their face image within the face guide frame.

[0006] Therefore, this disclosure proposes a technology that enables smooth identity verification of the subject of the photograph, regardless of their height. [Means for solving the problem]

[0007] The authentication device of this disclosure comprises a camera, a display unit, a control unit, and an authentication unit. The camera captures an image including a face image, which is an image of the face of a person being photographed. The display unit displays the face image. The control unit causes the display unit to display a guide frame on the display unit to guide the person being photographed to the correct position for capturing the face, based on the display position of the face image on the display unit. The authentication unit performs identity authentication using the face image when the face image is within the guide frame. [Effects of the Invention]

[0008] According to the disclosure technology, the subject of the photograph can be easily identified regardless of their height. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 shows an example of the appearance of the authentication device of Embodiment 1 of this disclosure. [Figure 2] Figure 2 shows an example of the installation of the authentication device according to Embodiment 1 of this disclosure. [Figure 3] Figure 3 shows an example of the configuration of the authentication device according to Embodiment 1 of this disclosure. [Figure 4] Figure 4 is a flowchart showing an example of the processing procedure in the authentication device of Embodiment 1 of this disclosure. [Figure 5] Figure 5 shows an example of the touchscreen display in Embodiment 1 of this disclosure. [Figure 6] FIG. 6 is a diagram showing a display example of the touch screen according to Embodiment 1 of the present disclosure. [Figure 7] FIG. 7 is a diagram showing a display example of the touch screen according to Embodiment 1 of the present disclosure. [Figure 8] FIG. 8 is a diagram showing a display example of the touch screen according to Embodiment 1 of the present disclosure. [Figure 9] FIG. 9 is a diagram showing a display example of the touch screen according to Embodiment 1 of the present disclosure. [Figure 10] FIG. 10 is a diagram showing a display example of the touch screen according to Embodiment 2 of the present disclosure. [Figure 11] FIG. 11 is a diagram showing an operation example of the authentication device according to Embodiment 3 of the present disclosure. [Figure 12] FIG. 12 is a diagram showing an operation example of the authentication device according to Embodiment 3 of the present disclosure. [Figure 13] FIG. 13 is a diagram showing a display example of the touch screen according to Embodiment 3 of the present disclosure. [Figure 14] FIG. 14 is a diagram showing an operation example of the authentication device according to Embodiment 4 of the present disclosure. [Figure 15] FIG. 15 is a diagram showing a display example of the touch screen according to Embodiment 4 of the present disclosure. [Figure 16] FIG. 16 is a diagram showing a display example of the touch screen according to Embodiment 4 of the present disclosure. [Figure 17] FIG. 17 is a diagram showing a display example of the touch screen according to Embodiment 4 of the present disclosure.

MODE FOR CARRYING OUT THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described based on the drawings. The same components in the drawings are denoted by the same reference numerals.

[0011] [Embodiment 1] [Appearance of the Authentication Device] FIG. 1 is a diagram showing an example of the appearance of the authentication device according to Embodiment 1 of the present disclosure. In FIG. 1, the authentication device 10 includes a camera 11, a touch screen 12, an IC card insertion slot 13, and an IC card reader 14. An IC card inserted into the IC card insertion slot 13 stores a face image of the owner of the IC card. The authentication device 10 performs authentication of the person being photographed by the camera 11 by comparing the face image registered in the IC card inserted into the IC card insertion slot 13 with the face image photographed by the camera 11.

[0012] <Installation of the authentication device> FIG. 2 is a diagram showing an example of the installation of the authentication device according to Embodiment 1 of the present disclosure. As shown in FIG. 2, the authentication device 10 is installed on a stand ST having a height SH. The camera 11 included in the authentication device 10 is a wide-angle camera having an angle of view AV of 85 degrees or more and 105 degrees or less in the vertical direction. For example, when the predetermined angle of view AV of the camera 11 in the vertical direction is 85 degrees or more and 105 degrees or less, and the authentication device 10 is installed in accordance with a photographed person TP having a height BH of 155 cm, the authentication device 10 is installed on a stand ST having a height SH of 70 cm. Also, the height EL of the line of sight of the photographed person TP having a height BH of 155 cm is generally about 145 cm, and the photographed person TP is usually photographed by the camera 11 while standing at a position about 30 cm away from the authentication device 10. Therefore, the orientation of the camera 11 in the vertical direction is preferably adjusted so that the angle AN formed by the straight line SL connecting the camera 11 and the position of the eyes of the photographed person TP and the optical axis OA of the camera 11 is about 28 degrees when the authentication device 10 is installed on a stand ST having a height SH of 70 cm.

[0013] <Configuration of the authentication device> Figure 3 shows an example configuration of an authentication device according to Embodiment 1 of this disclosure. In Figure 3, the authentication device 10 includes a camera 11, a touchscreen 12, an IC card reader 14, a face detection unit 15, a feature extraction unit 16, a personal authentication unit 17, and a display control unit 18. When an IC card is inserted into the IC card slot 13, the camera 11, which has a predetermined field of view, takes pictures at a constant frame rate and captures an image that includes an image of the person being photographed facing the authentication device 10 (hereinafter sometimes referred to as the "person image"). Hereinafter, the image captured by the camera 11 may be referred to as the "camera image". The camera image is output from the camera 11 to the touchscreen 12, the face detection unit 15, the feature extraction unit 16, the personal authentication unit 17, and the display control unit 18. The camera image is displayed on the touchscreen 12. The IC card reader 14 reads the face image registered on the IC card inserted into the IC card slot 13 (hereinafter sometimes referred to as the "registered face image") from the IC card. The touchscreen 12 is an example of a display unit that displays a face image. Other examples of display units that display a face image include liquid crystal displays. The face detection unit 15, feature extraction unit 16, user authentication unit 17, and display control unit 18 are implemented as hardware by processors such as CPUs (Central Processing Units), DSPs (Digital Signal Processors), FPGAs (Field Programmable Gate Arrays), and ASICs (Application Specific Integrated Circuits). The IC card reading unit 14 is implemented as hardware by an IC card reader, for example.

[0014] <Processing Procedure in Authentication Devices> Figure 4 is a flowchart illustrating an example of the processing procedure in the authentication device of Embodiment 1 of this disclosure. Figures 5 to 9 show examples of the touchscreen display of Embodiment 1 of this disclosure.

[0015] In step S100, the face detection unit 15 attempts to detect a face in the camera image CI.

[0016] Next, in step S105, the face detection unit 15 determines whether or not it succeeded in detecting a face in step S100. As shown in Figure 5, the camera image CI displayed on the touchscreen 12 includes the subject image PI. The subject image PI also includes the face image FI. The face detection unit 15 determines that face detection on the camera image CI has failed if only a part of the face image FI is included in the camera image CI, and determines that face detection on the camera image CI has succeeded if the entire face image FI is included in the camera image CI. If face detection on the camera image CI fails (step S105: No), the process proceeds to step S110, and if face detection on the camera image CI is successful (step S105: Yes), the process proceeds to step S115.

[0017] In step S110, the display control unit 18 displays the message "Please show your entire face" in the message display field MS set on the touchscreen 12, as shown in Figure 5. Also in step S110, the display control unit 18 does not display the face guide frame on the touchscreen 12. After the processing in step S110, the process returns to step S100.

[0018] On the other hand, in step S115, the display control unit 18 detects the position of the area center CE of the face image FI (hereinafter sometimes referred to as the "face image center") in the camera image CI as the display position of the face image FI in the camera image CI. The display control unit 18 then determines whether or not the face image center CE is within the reference range CR in the vertical direction of the camera image CI. The reference range CR is preferably set near the position where distortion is minimized in the camera image CI captured by the wide-angle camera 11, that is, near the center of the field of view AV. If the face image center CE is not within the reference range CR (step S115: No), the process proceeds to step S120, and if the face image center CE is within the reference range CR (step S115: Yes), the process proceeds to step S125.

[0019] In step S120, the display control unit 18 determines whether the center of the face image CE is lower than the reference range CR. If the center of the face image CE is lower than the reference range CR (step S120: Yes), the process proceeds to step S130. If the center of the face image CE is higher than the reference range CR (step S120: No), the process proceeds to step S135.

[0020] In step S125, as shown in Figure 6, since the center CE of the face image is within the reference range CR, the display control unit 18 displays a medium-sized, for example, dotted and orange face guide frame GF1 on the touchscreen 12. The lengths of all four sides of the face guide frame GF1 are the same. Also in step S125, as shown in Figure 6, the display control unit 18 displays the face guide frame GF1 on the touchscreen 12 by aligning the top edge of the face guide frame GF1 with the top of the face image FI TH in the vertical direction of the camera image CI. Also in step S125, as shown in Figure 6, the display control unit 18 displays the face guide frame GF1 on the touchscreen 12 by aligning the center of the face guide frame GF1 with the center of the camera image CI in the horizontal direction of the camera image CI.

[0021] In step S130, as shown in Figure 7, since the center CE of the face image is lower than the reference range CR, the display control unit 18 displays a large face guide frame GF2 on the touchscreen 12, for example, a dotted line and orange color. The lengths of all four sides of the face guide frame GF2 are the same. Also in step S130, as shown in Figure 7, the display control unit 18 displays the face guide frame GF2 on the touchscreen 12 by aligning the top edge of the face guide frame GF2 with the top of the face image FI TH in the vertical direction of the camera image CI. Also, the display control unit 18 displays the face guide frame GF2 on the touchscreen 12 by aligning the center of the face guide frame GF2 with the center of the camera image CI in the horizontal direction of the camera image CI. Also in step S130, as shown in Figure 7, the display control unit 18 displays the message "Please align your face with the frame" in the message display field MS.

[0022] In step S135, as shown in Figure 8, since the center CE of the face image is higher than the reference range CR, the display control unit 18 displays a small face guide frame GF3 on the touchscreen 12, for example, a dotted line and orange color. The lengths of all four sides of the face guide frame GF3 are the same. Also in step S135, as shown in Figure 8, the display control unit 18 displays the face guide frame GF3 on the touchscreen 12 by aligning its top edge with a predetermined amount α lower than the top of the head TH of the face image FI in the vertical direction of the camera image CI. Also, in the horizontal direction of the camera image CI, the display control unit 18 displays the face guide frame GF3 on the touchscreen 12 by aligning its center with the center of the camera image CI. Also in step S135, as shown in Figure 8, the display control unit 18 displays the message "Please align your face with the frame" in the message display field MS.

[0023] After processing in steps S125, S130, or S135, the process proceeds to step S140. Hereafter, face guide frames GF1, GF2, and GF3 may be collectively referred to as "face guide frame GF".

[0024] Here, the display position of the face image FI shown in Figure 6 is higher than the display position of the face image FI shown in Figure 7, and the display position of the face image FI shown in Figure 8 is higher than the display position of the face image FI shown in Figure 6. Also, the size of face guide frame GF1 is smaller than the size of face guide frame GF2, and the size of face guide frame GF3 is smaller than the size of face guide frame GF1. In other words, the display control unit 18 displays smaller guide frames GF on the touchscreen 12 as the display position of the face image FI moves higher above the camera image CI.

[0025] In step S140, the face detection unit 15 detects the positions of both eyes in the face image FI and determines whether the distance between the eyes (hereinafter sometimes referred to as "inter-eye distance") is greater than or equal to the threshold THD. If the inter-eye distance is greater than or equal to the threshold THD (step S140: Yes), the process proceeds to step S145; if the inter-eye distance is less than the threshold THD (step S140: No), the process returns to step S100.

[0026] In step S145, the face detection unit 15 determines whether the face image FI is contained within the face guide frame GF. If the face image FI is contained within the face guide frame GF (step S145: Yes), the process proceeds to step S150; if the face image FI is not contained within the face guide frame GF (step S145: No), the process returns to step S100.

[0027] In step S150, the feature extraction unit 16 attempts to extract features from the face image FI.

[0028] Next, in step S155, the feature extraction unit 16 determines whether or not it has succeeded in extracting the features of the face image FI. If it succeeds in extracting the features of the face image FI (step S155: Yes), the process proceeds to step S160; if it fails to extract the features of the face image FI (step S155: No), the process returns to step S100.

[0029] Next, in step S160, as shown in Figure 9, the display control unit 18 displays, for example, a solid blue face guide frame GFS on the touchscreen 12 and displays the message "Face recognized" in the message display field MS. When the process of step S160 is performed after the process of step S125, the size and position of the face guide frame GFS are the same as the size and position of the face guide frame GF1. Also, when the process of step S160 is performed after the process of step S130, the size and position of the face guide frame GFS are the same as the size and position of the face guide frame GF2. Also, when the process of step S160 is performed after the process of step S135, the size and position of the face guide frame GFS are the same as the size and position of the face guide frame GF3.

[0030] Next, in step S165, the personal authentication unit 17 extracts feature quantities from the registered face image and compares the feature quantities of the registered face image with the feature quantities of the face image FI extracted in step S150. By matching the registered face image with the face image FI in the camera image, the unit performs personal authentication of the person being photographed.

[0031] The above describes Example 1.

[0032] [Example 2] <Operation of the authentication device and display on the touchscreen> Figure 10 shows an example of the touchscreen display in Embodiment 2 of this disclosure.

[0033] The display control unit 18 determines whether the center of the face image CE is lower than the reference range CR. Figure 10 shows an example where the center of the face image CE is lower than the reference range CR. When the center of the face image CE is lower than the reference range CR, the face detection unit 15 detects the positions of both eyes in the face image FI and determines whether the inter-eye distance is less than the threshold THI (where threshold THI < threshold THD). If the center of the face image CE is lower than the reference range CR and the inter-eye distance is less than the threshold THI, the display control unit 18 determines that the subject is standing at a predetermined distance or more away from the authentication device 10, and displays a medium-sized, for example, dotted and orange face guide frame GF4 on the touchscreen 12, displaying the guide frame GF4 at a predetermined position within the reference range CR. As shown in Figure 10, the predetermined position where the guide frame GF4 is displayed is, for example, the center of the reference range CR. The lengths of the four sides of the face guide frame GF4 are the same. Furthermore, as shown in Figure 10, the display control unit 18 displays the guide frame GF4 at a predetermined position within the reference range CR, and also displays the message "Please align your face with the frame" in the message display field MS.

[0034] In this case, if the upper edge of the face guide frame GF is aligned with the top of the head TH of the face image FI and displayed on the touchscreen 12 as in Example 1, the face guide frame GF will be displayed below the touchscreen 12 when the person being photographed is standing away from the authentication device 10. Therefore, when the person being photographed approaches the authentication device 10 to perform identity authentication, they will need to bend down in order to fit the face image FI within the face guide frame GF.

[0035] In contrast, as described above, when the subject of photography is standing away from the authentication device 10, the guide frame GF4 is displayed at a predetermined position within the reference range CR. This allows the face guide frame GF to be displayed slightly above the center of the touchscreen 12, eliminating the need for the subject to bend down when approaching the authentication device 10 for authentication. Thus, the convenience of the authentication device 10 can be improved.

[0036] Furthermore, Example 2 can be implemented in combination with Example 1. When Example 2 is implemented in combination with Example 1, the display control unit 18 displays the face guide frame GF at the position according to Example 1 if the face image center CE is not at a position lower than the reference range CR.

[0037] The above describes Example 2.

[0038] [Example 3] <Operation of the authentication device and display on the touchscreen> Figures 11 and 12 show examples of the operation of the authentication device according to Embodiment 3 of this disclosure. Figure 13 shows an example of the touchscreen display according to Embodiment 3 of this disclosure.

[0039] As shown in Figure 11, if the subject's face is located near a light source LS that is captured in the camera image CI, overexposure may occur in the surrounding image of the face image FI (hereinafter sometimes referred to as the "surrounding image"), which can reduce the accuracy of identity authentication.

[0040] Therefore, as shown in Figure 12, when the center CE of the face image is within the reference range CR, the display control unit 18 divides the camera image CI into a total of 64 rectangular regions (X1,Y1) to (X8,Y8), with 8 in the X direction and 8 in the Y direction, and calculates the average value of the brightness of multiple pixels contained in each region (X1,Y1) to (X8,Y8) (hereinafter sometimes referred to as the "regional brightness average"). The display control unit 18 also determines whether the regional brightness average of each region (X1,Y1) to (X8,Y8) is equal to or greater than the threshold THB. As an example, Figure 12 shows the case in the camera image CI where the average regional luminance of each region (X1,Y1), (X2,Y1), (X3,Y1), (X4,Y1), (X1,Y2), (X2,Y2), (X3,Y2), (X4,Y2), (X1,Y3), (X2,Y3), (X3,Y3), (X4,Y3), (X1,Y4), (X2,Y4), (X3,Y4), (X4,Y4), (X1,Y5), (X2,Y5), (X3,Y5), (X4,Y5) (these regions may be collectively referred to as "region RA" below) is determined to be greater than or equal to the threshold THB, and the average regional luminance of each region other than region RA (these regions may be collectively referred to as "region RB" below) is determined to be less than the threshold THB.

[0041] Furthermore, the display control unit 18 identifies the region located within a predetermined distance from the center CE of the face image among the 64 rectangular regions in the camera image CI as the region PR that forms the peripheral image (hereinafter sometimes referred to as the "peripheral image region"). For example, in the example shown in Figure 12, the display control unit 18 identifies the regions (X2,Y2), (X3,Y2), (X4,Y2), (X5,Y2), (X6,Y2), (X7,Y2), (X2,Y3), (X3,Y3), (X4,Y3), (X5,Y3), (X6,Y3), (X7,Y3), (X2,Y4), (X3,Y4), (X4,Y4), (X5,Y4), (X6,Y4), (X7,Y4), (X2,Y5), (X3,Y5), (X4,Y5), (X5,Y5), (X6,Y5), and (X7,Y5) as peripheral image regions PR from among the 64 rectangular regions in the camera image CI. Furthermore, in the peripheral image region PR, the regions where the average region brightness is greater than or equal to the threshold THB are (X2,Y2), (X3,Y2), (X4,Y2), (X2,Y3), (X3,Y3), (X4,Y3), (X2,Y4), (X3,Y4), (X4,Y4), (X2,Y5), (X3,Y5), and (X4,Y5).

[0042] Furthermore, in region RB shown in Figure 12, the entire range of regions (X5,Y3), (X6,Y3), (X7,Y3), (X8,Y3), (X5,Y4), (X6,Y4), (X7,Y4), (X8,Y4) and a portion of the upper range of regions (X5,Y5), (X6,Y5), (X7,Y5), (X8,Y5) overlap with the reference range CR. Hereafter, the region where region RB and the reference range CR overlap each other may be referred to as the "low-luminance overlap region".

[0043] Therefore, as shown in Figure 13, when the display control unit 18 displays a medium-sized, for example, dotted and orange face guide frame GF5 on the touchscreen 12, it displays the guide frame GF5 in the low-brightness overlap area. Also, as shown in Figure 13, the display control unit 18 displays the message "Please align your face with the frame" in the message display area MS while displaying the guide frame GF5 in the low-brightness overlap area.

[0044] In this way, when the brightness of the surrounding image of the face image FI is greater than or equal to the threshold THB, a guide frame GF5 is displayed at a position in the reference range CR where the brightness is less than the threshold THB. This guides the subject to move their face away from the light source LS, thus preventing overexposure in the surrounding image. Therefore, a decrease in the accuracy of identity authentication can be prevented.

[0045] Furthermore, Example 3 can be implemented in combination with Example 1 or Example 2. When Example 3 is implemented in combination with Example 1 or Example 2, the display control unit 18 displays the face guide frame GF at the position according to Example 1 if the average value of the area brightness of any of the areas is less than the threshold THB.

[0046] The above describes Example 3.

[0047] [Example 4] <Operation of the authentication device and display on the touchscreen> Figure 14 shows an example of the operation of the authentication device in Embodiment 4 of this disclosure. Figures 15, 16, and 17 show an example of the touchscreen display in Embodiment 4 of this disclosure.

[0048] As shown in Figure 14, when side light IR shines from the left of the camera 11 facing the subject, the left half of the face image FI (hereinafter sometimes referred to as the "left half image") FA becomes brighter, while the right half of the face image FI (hereinafter sometimes referred to as the "right half image") FB becomes darker. This creates a brightness difference between the left half image FA and the right half image FB, which can reduce the accuracy of identity authentication.

[0049] Therefore, the display control unit 18 first divides the camera image CI into a total of 64 rectangular regions (X1,Y1) to (X8,Y8), eight in the X direction and eight in the Y direction, as shown in Figure 12, similar to Embodiment 3, when the center CE of the face image is within the reference range CR.

[0050] Furthermore, the display control unit 18 identifies the regions that overlap with the face image FI from among the 64 rectangular regions (Figure 12) in the camera image CI (hereinafter sometimes referred to as "face image overlap regions"). For example, in the example shown in Figure 12, the display control unit 18 identifies the regions (X3,Y3), (X4,Y3), (X5,Y3), (X6,Y3), (X3,Y4), (X4,Y4), (X5,Y4), and (X6,Y4) from among the 64 rectangular regions in the camera image CI as face image overlap regions.

[0051] Furthermore, the display control unit 18 divides the face image overlap region (X3,Y3), (X4,Y3), (X5,Y3), (X6,Y3), (X3,Y4), (X4,Y4), (X5,Y4), (X6,Y4) into a region to the left of the face image center CE (hereinafter sometimes referred to as the "left region") and a region to the right of the face image center CE (hereinafter sometimes referred to as the "right region"), with the face image center CE as the reference point. Therefore, in the example shown in Figure 12, the display control unit 18 classifies the regions (X3,Y3), (X4,Y3), (X5,Y3), (X6,Y3), (X3,Y4), (X4,Y4), (X5,Y4), (X6,Y4) as the left region and the regions (X5,Y3), (X6,Y3), (X5,Y4), (X6,Y4) as the right region. However, the display control unit 18 may exclude regions that overlap with a vertical line passing through the center CE of the face image from both the left and right regions within the face image overlap region.

[0052] Furthermore, the display control unit 18 calculates the average value of the brightness of multiple pixels included in the left region (hereinafter sometimes referred to as the "average brightness of the left region") and the average value of the brightness of multiple pixels included in the right region (hereinafter sometimes referred to as the "average brightness of the right region"). The display control unit 18 also calculates the difference between the average brightness of the left region and the average brightness of the right region (hereinafter sometimes referred to as the "left-right region brightness difference") and determines whether the left-right region brightness difference is greater than or equal to the threshold THA. If the left-right region brightness difference is greater than or equal to the threshold THA, the display control unit 18 determines the relative magnitude of the average brightness of the left region and the average brightness of the right region. If the average brightness of the left region is greater than the average brightness of the right region, the display control unit 18 prompts the subject to turn their face to the left. On the other hand, if the average brightness of the right region is greater than the average brightness of the left region, the display control unit 18 prompts the subject to turn their face to the right.

[0053] The following are examples of notifications to the subject of a photograph regarding the direction their face should face. Examples 1, 2, and 3 below all illustrate how to instruct the subject to turn their face to the left.

[0054] <Notification Example 1 (Figure 15)> In Notification Example 1, as shown in Figure 15, the display control unit 18 displays a face guide frame GF6 on the touchscreen 12, which is a rectangle with a left side longer than the right side, for example, a dotted line and orange in color. The display control unit 18 also displays the message "Please align your face with the frame [slightly to the left]" in the message display field MS.

[0055] <Notification Example 2 (Figure 16)> In notification example 2, as shown in Figure 16, the display control unit 18 displays a medium-sized, for example, dotted and orange face guide frame GF7 on the touchscreen 12. The display control unit 18 also displays a left-pointing arrow mark AR on the touchscreen 12. Furthermore, the display control unit 18 displays the message "Please align your face with the frame [slightly to the left]" in the message display field MS.

[0056] <Notification Example 3 (Figure 17)> In notification example 3, as shown in Figure 17, the display control unit 18 displays a medium-sized, for example, dotted and orange face guide frame GF7 on the touchscreen 12. The display control unit 18 also displays an animation AM on the touchscreen 12 that mimics a person changing the direction of their face from facing forward to the left. The display control unit 18 also displays the message "Please align your face with the frame [slightly to the left]" in the message display field MS.

[0057] The above explains notification examples 1, 2, and 3.

[0058] Thus, when the difference in brightness between the left and right sides of the facial image FI is greater than or equal to the threshold THA, the subject is instructed to turn their face towards the side with greater brightness. This reduces the difference in brightness between the left half image FA and the right half image FB, thus preventing a decrease in the accuracy of identity authentication.

[0059] Furthermore, Example 4 can be implemented in combination with Example 1, Example 2, or Example 3. When Example 4 is implemented in combination with Example 1, Example 2, or Example 3, the display control unit 18 displays the face guide frame GF at the position according to Example 1.

[0060] The above describes Example 4.

[0061] [Example 5] <Authentication Program> All or part of each process in the authentication device 10 may be implemented by having the processor in the authentication device 10 execute a program corresponding to each process. For example, the program corresponding to each process in the authentication device 10 may be stored in the memory of the authentication device 10. Alternatively, the program corresponding to each process in the authentication device 10 may be stored on a program server connected to the authentication device 10 via any network, downloaded from the program server to the authentication device 10, and executed. Alternatively, the program corresponding to each process in the authentication device 10 may be stored on a recording medium readable by the authentication device 10, read from the recording medium, and executed.

[0062] The above describes Example 5.

[0063] [Example 6] <Configuration of the authentication device> Examples 1 to 5 describe the case where the authentication device 10 has a camera 11 and a touchscreen 12. However, the authentication device 10 does not have to have a camera 11 and a touchscreen 12. If the authentication device 10 does not have a camera 11 and a touchscreen 12, the camera 11 and the touchscreen 12 are connected to the authentication device 10 using wired or wireless connections. Alternatively, a display and a mouse may be used instead of the touchscreen 12.

[0064] The above describes Example 6.

[0065] In the example, identity authentication using a facial image registered on an IC card was given as one example. However, the disclosure technology can also be applied to identity authentication using a facial photograph included in identity verification documents such as a driver's license or passport. When identity authentication is performed using a facial photograph included in an identity verification document, the authentication device 10 has a camera for taking a facial photograph included in the identity verification document (hereinafter sometimes referred to as the "facial photograph camera"), and performs identity authentication of the person being photographed by camera 11 by comparing the facial image taken by the facial photograph camera with the facial image taken by camera 11.

[0066] As described above, the authentication device of this disclosure (authentication device 10 in the embodiment) comprises a camera (camera 11 in the embodiment), a display unit (touchscreen 12 in the embodiment), a control unit (display control unit 18 in the embodiment), and an authentication unit (personal authentication unit 17 in the embodiment). The camera captures an image (camera image CI in the embodiment) that includes a face image (face image FI in the embodiment), which is an image of the face of the person being photographed. The display unit displays the face image. Based on the display position of the face image on the display unit, the control unit causes a guide frame (face guide frame GF in the embodiment) to be displayed on the display unit to guide the person being photographed to the correct position for photographing their face. When the face image is within the guide frame, the authentication unit performs personal authentication using the face image.

[0067] For example, the control unit aligns the top edge of the guide frame with the top of the head in the facial image and displays the guide frame on the display unit.

[0068] By doing this, the height of the guide frame displayed for the subject in facial image authentication can be adjusted according to the subject's height, allowing the subject to be authenticated smoothly regardless of their height.

[0069] Furthermore, when the center of the face image is within a reference range in the vertical direction of the image containing the face image, or when it is located below the reference range, the control unit displays the guide frame on the display unit by aligning the top edge of the guide frame with the top of the face image. On the other hand, when the center of the face image is located above the reference range, the control unit displays the guide frame on the display unit by aligning the top edge of the guide frame with a predetermined amount below the top of the face image.

[0070] This encourages tall subjects to lower their heads, thus preventing a decrease in the authentication rate for tall subjects.

[0071] Furthermore, the control unit displays a smaller guide frame on the display unit as the position of the face image on the display unit moves higher up the image containing the face image.

[0072] This prevents a decrease in the authentication rate when a tall subject stands far enough away from the authentication device to fit within the camera's field of view.

[0073] Furthermore, the control unit displays a guide frame at a predetermined position within the reference range if the center of the face image is located below a reference range in the vertical direction of the image containing the face image, and the distance between the eyes in the face image is less than a threshold.

[0074] This eliminates the need for the subject to bend down when undergoing identity verification, thus improving the convenience of the authentication device.

[0075] Furthermore, the control unit displays a guide frame at a position within the reference range where the brightness is below the threshold if the center of the face image is within the vertical reference range of the image containing the face image, and the brightness of the surrounding image in the image containing the face image is above a threshold.

[0076] This prevents overexposure in the surrounding area of ​​the facial image, thus preventing a decrease in the accuracy of identity verification.

[0077] Furthermore, if the center of the face image is within the vertical reference range of the image containing the face image, and the difference in brightness between the left and right sides of the face image is greater than or equal to a threshold, the control unit prompts the subject to turn their face towards the side with greater brightness.

[0078] By doing this, the difference in brightness between the left and right sides of the facial image can be reduced, thus preventing a decrease in the accuracy of identity verification. [Explanation of Symbols]

[0079] 10 Authentication device 11 Cameras 12 Touchscreen 14 IC card reader 15 Face detection unit 16 Feature Extraction Unit 17. Identity Verification Department 18 Display Control Unit

Claims

1. a camera that captures an image including a facial image that is an image of the face of a subject; a display unit that displays the facial image; a control unit that displays a guide frame on the display unit to guide the subject to a photographing position of the face; an authentication unit that performs identity authentication using the face image; Equipped with the control unit determines the display position or the display size of the guide frame based on whether the display position of the face image on the display unit is within a reference range. Authentication device.

2. the control unit causes the display unit to display the guide frame with an upper side of the guide frame aligned with the top of the head of the face image. The authentication device according to claim 1 .

3. The control unit when the predetermined position of the face image is within the reference range in the vertical direction of the image including the face image, or is at a position lower than the reference range, displaying the guide frame on the display unit with the top of the head of the face image aligned with the upper side of the guide frame; When the predetermined position is higher than the reference range, the guide frame is displayed on the display unit with the upper side aligned to a position lower than the top of the head of the face image by a predetermined amount. The authentication device according to claim 1 .

4. the control unit causes the display unit to display the guide frame in a smaller size as the display position is located higher on the image including the face image. The authentication device according to claim 1 .

5. the control unit, when a predetermined position of the face image is lower than the reference range in the vertical direction of the image including the face image and the distance between the eyes in the face image is less than a threshold, displays the guide frame at a predetermined position within the reference range. The authentication device according to claim 1 .

6. when a predetermined position of the face image is within the reference range in the vertical direction of the image including the face image and the brightness of an image around the face image in the image including the face image is equal to or greater than a threshold, the control unit displays the guide frame at a position within the reference range where the brightness is less than the threshold. The authentication device according to claim 1 .

7. the control unit prompts the person to turn their face toward the left or right side with greater brightness when a predetermined position of the face image is within the reference range in the vertical direction of the image including the face image and a difference in brightness between the left and right sides of the face image is equal to or greater than a threshold value; The authentication device according to claim 1 .

8. a camera that captures an image including a facial image that is an image of the face of a subject; a display unit that displays the facial image; an authentication unit that performs identity authentication using the face image; A guide frame display method in an authentication device comprising: Detecting a display position of the face image on the display unit; determining a display position or a display size of a guide frame to be displayed on the display unit to guide the subject to a photographing position of the face based on whether the display position is within a reference range; Guide frame display method.

9. a camera that captures an image including a facial image that is an image of the face of a subject; a display unit that displays the facial image; An authentication program applicable to an authentication device comprising: Detecting a display position of the face image on the display unit; determining a display position or a display size of a guide frame to be displayed on the display unit to guide the subject to a photographing position of the face based on whether the display position is within a reference range; performing identity authentication using the face image; An authentication program that allows a processor to perform processing.

Images